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In all cases examined, the deformation is localized within a rather small number of deformation bands.
As recrystallized grains also have been observed along the crack front in failed TMF specimens, see figure 4, it is clear that recrystallization is implicated in the phenomena leading to final failure of the material during TMF.
Since the absence of grain boundary strengthening elements in these materials is known to lead to premature failure of a recrystallized zone, it is of major interest to understand the details of the recrystallization process occurring under TMF conditions.
Figure 5: Illustration of the nucleation of recrystallized grains at the intercept of two propagating twins: (a) EBSD map, (b) SEM image.

A number of paramagnetic defects and defect complexes in BaTiO3 have been detected by the Electron Paramagnetic Resonance (EPR) technique.
EPR can be detected a number of paramagnetic defects and associated defects with unpaired electron spins in point defect structure and distribution in doped BaTiO3 PTCR ceramics.
As is well known that the PTCR effect requires the presence of in-gap electron states at the grain interface or near the grain boundary.

Influence of Grain Size on the Setting of Portland Cement: a Stray-Field Magnetic Resonance Imaging Study Teresa G.
Introduction A number of failures of large concrete structures during construction have been reported in the last decades [1].
The concentration gradient across the membrane increases with ongoing grain dissolution by water within the gel coating and the consequent osmotic pressure build up forces the water to diffuse into the gel; this dormant period ends with the membrane rupture.

(3) with N as Avogadro's number, h and kB the Planck and Boltzmann constants.
Perrin description of the active state, it appears that a rather large number (> 5) of quanta of energy are required for activation.
The case of grain boundary and interphase diffusion is not so clear: apart the case of self diffusion, in many measurements of diffusivity or mobility, the compensation temperature is rather close to the temperature range of the experiments [30].
It is also observed in equilibrium phenomena, such as the equilibrium composition of surface or grain boundaries (equilibrium segregation).
Philibert: I suspect that Arrhenius law originates in the spectrum of some basic variables - which could be the number and amplitudes of the phonons whose addition produces the jump - but also the spectrum of barrier heights or the spectrum of hops in alloys.

In the plasma-carburizing method, the detrimental grain boundary oxides in the surface of the materials and sooting problems are eliminated and the high carbon content near the surface is easily achieved.
Recently, the plasma-carburizing method was developed, in which the detrimental grain boundary oxides in the surface of the materials and sooting problems are eliminated and the high carbon content near the surface is easily achieved [1].
The number of load cycles, at which the test machine stops by the vibration due to the initiation of the failure (corresponding to failure area ratio > 2%) on the roller surface, was regarded as the contact fatigue life.
Contact fatigue limit σHu GPa Contact fatigue limit ratio σHu /σHuO Amount of wear v mm3 Arc height h mmA Number of load cycles N Case depth d mm Number of load cycles N increase of h.
Figure 10 shows the relations between the average amount of wear v of L and H rollers and the number of load cycles N for Hertz stress σH = 2.1GPa.

A small number of secondary phase of Bi2O3 appeared when the content of CB exceeds 5.0 wt%.
This may be due to the effect of the low eutectic point of CB which transformed into liquid phase below 600°C[6].The highest sintering temperature (1100°C) produced large uniform grains (~2µm).
The samples with 5.0 wt% and 10.0 wt% CB addition appeared some large anomalous grains, which may attributed to the sintering in presence of liquid phase [8].
The dielectric constant of pure BST is lower than that of BST with 1.0 % and 2.0 wt% CB, which may attributed to low density [10] and the smaller grain size [11].

Although this material posses a number of advantages, such as high energy density, high theoretical specific capacity (170 mAhg-1), remarkable thermal stability and safety [1-3], and it exhibits only a small fade even after several hundreds of cycles [4], its main drawback is poor electrochemical performance in high rate dischargeability (HRD) due to its low electronic conductivity and low lithium ions diffusivity [5-7].
(a)1:3 (b)1:1.5 (c) 1:1 (d) 1:0.75 Fig. 2 shows SEM images of the synthesized LiFePO4/C composites at different CA/OA ratios.It can be seen from Fig. 2 that the grains are approximate spherical shape and their size distribution is narrow.
There are some aggregated particles.The grain size decreased with increasing CA/OA ratios.
Thus, this could be reason that the grain size decreases with increasing CA/OA ratios.

The use of wrought magnesium alloys has been restricted by the limited ductility that these materials exhibit at room temperature, due to the low number of available (basal) slip systems.
At room temperature the microstructure is similar to the as received material since the sheet cracks before reaching an appreciable strain, whereas at 250°C the grains undergo recrystallization (static and/or dynamic) with very fine grains as shown in Fig. 7b.
The microstructure at RT and 250°C of the deformed samples was analysed by means of LOM; at RT the grains were mainly equiaxed and coarser than at 250°C, since at 250°C the recrystallization phenomena occur during deformation.

The layers were obtained by spray pyrolysis deposition (SPD), at previously optimized deposition parameters, [4]; for each sample the total number of deposition sequences is 30, the deposition temperature was 300 °C and the carrier gas was air at 1.4 bars.
The samples using hydrophobic polymers (W_2.5B and W_5B) have large gap area between the grains, while hydrophilic polymers (W_2.5L and W_5L), grains with various size are forming a compact morphology.
The samples W_2.5B and W_2.5B_0.5Cd have similar morphologies but different pore diameters and grain sizes, confirming the XRD results. 3.2.

For conventional magnesium alloys such as AZ31, AZ61 and AZ91D, a large number of studies have been carried out on the friction and wear behavior [9-11].
The spot B is Mg17Al12 phase that distributed at grain boundary, and a little Mn and Y element is inclined to be rich in Mg17Al12 phase.
The Mg17Al12 phases are distributed mainly at grain boundaries, either forming a discontinuous network as Fig. 2 (a) illustrates.
Also with the addition of Y, the grain size decreases.